cleanups

implement TclCommand.TclCommandSignaled as proof of concept (not usefull)
bypass using threads  within obj.generatecncjob(use_thread = False, **args)
reimplement some more shell commands  to  OOP style

tclCommands/TclCommandExteriors.py

@@ -8,7 +8,7 @@ class TclCommandExteriors(TclCommand.TclCommand):
     """
 
     # array of all command aliases, to be able use  old names for backward compatibility (add_poly, add_polygon)
-    aliases = ['exteriors','ext']
+    aliases = ['exteriors', 'ext']
 
     # dictionary of types from Tcl command, needs to be ordered
     arg_names = collections.OrderedDict([
@@ -30,7 +30,7 @@ class TclCommandExteriors(TclCommand.TclCommand):
             ('name', 'Name of the source Geometry object.'),
             ('outname', 'Name of the resulting Geometry object.')
         ]),
-        'examples':[]
+        'examples': []
     }
 
     def execute(self, args, unnamed_args):
@@ -50,19 +50,15 @@ class TclCommandExteriors(TclCommand.TclCommand):
         else:
             outname = name + "_exteriors"
 
-        try:
-            obj = self.app.collection.get_by_name(name)
-        except:
-            self.app.raiseTclError("Could not retrieve object: %s" % name)
-
+        obj = self.app.collection.get_by_name(name)
         if obj is None:
-            self.app.raiseTclError("Object not found: %s" % name)
+            self.raise_tcl_error("Object not found: %s" % name)
 
         if not isinstance(obj, Geometry):
-            self.app.raiseTclError('Expected Geometry, got %s %s.' % (name, type(obj)))
+            self.raise_tcl_error('Expected Geometry, got %s %s.' % (name, type(obj)))
 
-        def geo_init(geo_obj, app_obj):
+        def geo_init(geo_obj):
             geo_obj.solid_geometry = obj_exteriors
 
         obj_exteriors = obj.get_exteriors()
-        self.app.new_object('geometry', outname, geo_init)
+        self.app.new_object('geometry', outname, geo_init)